[PATCH AUTOSEL 4.14 033/105] net: stmmac: dwmac4: fix flow control issue

Sasha Levin
2019-07-15T14:52:37Z

From: Biao Huang <biao.huang@mediatek.com>

[ Upstream commit ee326fd01e79dfa42014d55931260b68b9fa3273 ]

Current dwmac4_flow_ctrl will not clear
GMAC_RX_FLOW_CTRL_RFE/GMAC_RX_FLOW_CTRL_RFE bits,
so MAC hw will keep flow control on although expecting
flow control off by ethtool. Add codes to fix it.

Fixes: 477286b53f55 ("stmmac: add GMAC4 core support")
Signed-off-by: Biao Huang <biao.huang@mediatek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
index ed5fcd4994f2..8445af580cb6 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -474,8 +474,9 @@ static void dwmac4_flow_ctrl(struct mac_device_info *hw, unsigned int duplex,
if (fc & FLOW_RX) {
pr_debug("\tReceive Flow-Control ON\n");
flow |= GMAC_RX_FLOW_CTRL_RFE;
- writel(flow, ioaddr + GMAC_RX_FLOW_CTRL);
}
+ writel(flow, ioaddr + GMAC_RX_FLOW_CTRL);
+
if (fc & FLOW_TX) {
pr_debug("\tTransmit Flow-Control ON\n");

@@ -483,7 +484,7 @@ static void dwmac4_flow_ctrl(struct mac_device_info *hw, unsigned int duplex,
pr_debug("\tduplex mode: PAUSE %d\n", pause_time);

for (queue = 0; queue < tx_cnt; queue++) {
- flow |= GMAC_TX_FLOW_CTRL_TFE;
+ flow = GMAC_TX_FLOW_CTRL_TFE;

if (duplex)
flow |=
@@ -491,6 +492,9 @@ static void dwmac4_flow_ctrl(struct mac_device_info *hw, unsigned int duplex,

writel(flow, ioaddr + GMAC_QX_TX_FLOW_CTRL(queue));
}
+ } else {
+ for (queue = 0; queue < tx_cnt; queue++)
+ writel(0, ioaddr + GMAC_QX_TX_FLOW_CTRL(queue));
}
}

--
2.20.1